/*
* Licensed to the Apache Software Foundation (ASF) Under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for Additional information regarding copyright ownership.
* The ASF licenses this file to You Under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed Under the License is distributed on an "AS Is" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations Under the License.
*/

namespace Zephyr.Utils.NPOI.SS.Formula.Eval
{
    using System;
    using Zephyr.Utils.NPOI.SS.Formula;
    using Zephyr.Utils.NPOI.SS.Formula.Functions;

    /**
     * @author Amol S. Deshmukh &lt; amolweb at ya hoo dot com &gt;
     *  
     */
    public class UnaryMinusEval : Fixed1ArgFunction
    {

        public static Function instance = new UnaryMinusEval();

        private UnaryMinusEval()
        {
        }


        public override ValueEval Evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0)
        {
            double d;
            try
            {
                ValueEval ve = OperandResolver.GetSingleValue(arg0, srcRowIndex, srcColumnIndex);
                d = OperandResolver.CoerceValueToDouble(ve);
            }
            catch (EvaluationException e)
            {
                return e.GetErrorEval();
            }
            if (d == 0.0)
            { // this '==' matches +0.0 and -0.0
                return NumberEval.ZERO;
            }
            return new NumberEval(-d);
        }
    }
}